A new type of chiral conjugated polymers 6a-d has been synthesized by the reaction of (R)-2,2'-dihydroxy-1,1'-binaphthyl-6,6'-dicarbaldehyde 5 with corresponding diamine in the presence of acetic acid.
The 1,2'-binaphthol based oligomers 3 and 7 with 3,3'-acetylene-phenylene-acetylene spacer were prepared from BINOL 1. The high optical rotation value and CD spectra demonstrated the main chain chirality of th...The 1,2'-binaphthol based oligomers 3 and 7 with 3,3'-acetylene-phenylene-acetylene spacer were prepared from BINOL 1. The high optical rotation value and CD spectra demonstrated the main chain chirality of the oligomer molecule. The UV-VIS and fluorescent spectra evidence the characteristics of conjugated structure. In comparison with oligomer 2 bearing 3,3'-acetylene spacer, the oligomers 3 and 7 have longer efficient conjugation segment, and their fluorescent quantum yields (phi) increased (0.60-0.65 versus 0.14). Extending the effective conjugation segment would improve the photophysical properties of chiral conjugated polymers.展开更多
Four binol based pyrrole carboxamide chiral receptors has been synthesized and effectively used as a Chirality Conversion Reagent (CCR) for underivatized amino acids. Three points of interactions take place for the co...Four binol based pyrrole carboxamide chiral receptors has been synthesized and effectively used as a Chirality Conversion Reagent (CCR) for underivatized amino acids. Three points of interactions take place for the conversion process. They are the reversible imine formation, the internal resonance assisted Hydrogen Bonding (RAHB) and the additional hydrogen bonds between the amino acids and the heterocylic moiety of the pendant groups. The conversion efficiency of all the receptors was found to be comparable with those of the receptors reported earlier.展开更多
The synthesis of a new type of polymers with main chain chirality based on BINOL skeleton is described. Titanium-BINOLate catalysts are easily generated from these polymers and applied to the asymmetric reaction of Et...The synthesis of a new type of polymers with main chain chirality based on BINOL skeleton is described. Titanium-BINOLate catalysts are easily generated from these polymers and applied to the asymmetric reaction of Et2Zn with benzaldehyde. The products are obtained in good yields with moderate enantioselectivities.展开更多
New functional dendrimers bearing 4, 8 and 16 axial chiral units on their surface were synthesized from achiral PAMAM dendrimers and axial chiral (R)-BINOL derivative.
Chiral polymers P-1 and P-2 were synthesized by the polymerization of （R）-3,3＇-diiodo-2,2＇-bisbutoxy-1,1＇- binaphthyl （M- 1 ） with 2,5-di（4-ethynylphenyl）- 1,3,4-oxadiazole （M-3） and （R）-3,3＇-diethylnyl-...Chiral polymers P-1 and P-2 were synthesized by the polymerization of （R）-3,3＇-diiodo-2,2＇-bisbutoxy-1,1＇- binaphthyl （M- 1 ） with 2,5-di（4-ethynylphenyl）- 1,3,4-oxadiazole （M-3） and （R）-3,3＇-diethylnyl-2,2＇-bisbutoxy- 1,1 ＇-binaphthyl （M-2） with 1,2-di（4-bromophenyl）acetylene （M-4） under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-Vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and CD spectroscopy. CD spectra of P-1 and P-2 are similar due to the same chiral center units and main chain structure. The long wavelengths CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure and a highly rigid backbone in the polymer chain. Polymers have strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the polymers to the chiral binaphthyl core and are expected to provide understanding of the relationship between molecular structure and fluorescent property of the chiral polymers.展开更多
Polymer and polymer were obtained by the polymerization of (R)-6,6'-dibromo-2,2'-binaphtho-20-crown-6 (M-1) and (R)-6,6'-dibromo-2,2'-di(methoxyethoxymethyloxy)-1,1'-binaphthyl (M-2) with p-divinyl...Polymer and polymer were obtained by the polymerization of (R)-6,6'-dibromo-2,2'-binaphtho-20-crown-6 (M-1) and (R)-6,6'-dibromo-2,2'-di(methoxyethoxymethyloxy)-1,1'-binaphthyl (M-2) with p-divinylbenzene under Pd- catalyzed Heck reaction. The UV, fluorescence and CD spectra of polymer are similar due to the same linkers present in their polymer chain. Polymers can emit strong blue fluorescence and are expected to have potential applications in polarized blue-light emitting sensors. The chiral conjugated polymers exhibit a strong Cotton effect in their circular dichroism (CD) spectra, indicating a high rigidity of polymer backbone.展开更多
Soluble polymeric chiral binaphthol （BINOL） ligands have been synthesized through copolymerization of 3,3′-bis（hydroxymethyl）-2,2′-bis（methoxymethy leneoxy）-1,1′-binaphthyl,1,6-dihydroxyhexane and 1,4-benzene...Soluble polymeric chiral binaphthol （BINOL） ligands have been synthesized through copolymerization of 3,3′-bis（hydroxymethyl）-2,2′-bis（methoxymethy leneoxy）-1,1′-binaphthyl,1,6-dihydroxyhexane and 1,4-benzene dicarbonyl chloride followed by deprotection of methoxymethyleneoxy groups by iPrOH/HCl,and their application in the enantioselective addition of diethylzinc to benzaldehyde was investigated.All soluble polymeric chiral BINOL ligands were characterized by IR、 1H-NMR、GPC and elemental analysis,which clearly demonstrated the formation of polymeric chiral BINOL ligands.These soluble polymeric chiral ligands were found to be effective in the addition of diethylzinc to benzaldehyde either in the presence or in the absence of Ti（Oi Pr）4 with higher catalytic activities and lower enantioselectivities.In the latter case,the dendritic chiral BINOL ligands showed much higher catalytic activity and a little higher enantioselectivity than BINOLs.展开更多
文摘A new type of chiral conjugated polymers 6a-d has been synthesized by the reaction of (R)-2,2'-dihydroxy-1,1'-binaphthyl-6,6'-dicarbaldehyde 5 with corresponding diamine in the presence of acetic acid.
基金This work was supported support by National Natural Science Foundation of China, Tulane University and the Center for Photoinduced Processes funded by the NSF of USA.
文摘The 1,2'-binaphthol based oligomers 3 and 7 with 3,3'-acetylene-phenylene-acetylene spacer were prepared from BINOL 1. The high optical rotation value and CD spectra demonstrated the main chain chirality of the oligomer molecule. The UV-VIS and fluorescent spectra evidence the characteristics of conjugated structure. In comparison with oligomer 2 bearing 3,3'-acetylene spacer, the oligomers 3 and 7 have longer efficient conjugation segment, and their fluorescent quantum yields (phi) increased (0.60-0.65 versus 0.14). Extending the effective conjugation segment would improve the photophysical properties of chiral conjugated polymers.
文摘Four binol based pyrrole carboxamide chiral receptors has been synthesized and effectively used as a Chirality Conversion Reagent (CCR) for underivatized amino acids. Three points of interactions take place for the conversion process. They are the reversible imine formation, the internal resonance assisted Hydrogen Bonding (RAHB) and the additional hydrogen bonds between the amino acids and the heterocylic moiety of the pendant groups. The conversion efficiency of all the receptors was found to be comparable with those of the receptors reported earlier.
文摘The synthesis of a new type of polymers with main chain chirality based on BINOL skeleton is described. Titanium-BINOLate catalysts are easily generated from these polymers and applied to the asymmetric reaction of Et2Zn with benzaldehyde. The products are obtained in good yields with moderate enantioselectivities.
文摘New functional dendrimers bearing 4, 8 and 16 axial chiral units on their surface were synthesized from achiral PAMAM dendrimers and axial chiral (R)-BINOL derivative.
基金This work was supported by the National Natural Science Foundation of China (No. 20474028)Jiangsu Provincial Natural Science Foundation (No. BK2004086)
文摘Chiral polymers P-1 and P-2 were synthesized by the polymerization of （R）-3,3＇-diiodo-2,2＇-bisbutoxy-1,1＇- binaphthyl （M- 1 ） with 2,5-di（4-ethynylphenyl）- 1,3,4-oxadiazole （M-3） and （R）-3,3＇-diethylnyl-2,2＇-bisbutoxy- 1,1 ＇-binaphthyl （M-2） with 1,2-di（4-bromophenyl）acetylene （M-4） under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-Vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and CD spectroscopy. CD spectra of P-1 and P-2 are similar due to the same chiral center units and main chain structure. The long wavelengths CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure and a highly rigid backbone in the polymer chain. Polymers have strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the polymers to the chiral binaphthyl core and are expected to provide understanding of the relationship between molecular structure and fluorescent property of the chiral polymers.
文摘Polymer and polymer were obtained by the polymerization of (R)-6,6'-dibromo-2,2'-binaphtho-20-crown-6 (M-1) and (R)-6,6'-dibromo-2,2'-di(methoxyethoxymethyloxy)-1,1'-binaphthyl (M-2) with p-divinylbenzene under Pd- catalyzed Heck reaction. The UV, fluorescence and CD spectra of polymer are similar due to the same linkers present in their polymer chain. Polymers can emit strong blue fluorescence and are expected to have potential applications in polarized blue-light emitting sensors. The chiral conjugated polymers exhibit a strong Cotton effect in their circular dichroism (CD) spectra, indicating a high rigidity of polymer backbone.
文摘Soluble polymeric chiral binaphthol （BINOL） ligands have been synthesized through copolymerization of 3,3′-bis（hydroxymethyl）-2,2′-bis（methoxymethy leneoxy）-1,1′-binaphthyl,1,6-dihydroxyhexane and 1,4-benzene dicarbonyl chloride followed by deprotection of methoxymethyleneoxy groups by iPrOH/HCl,and their application in the enantioselective addition of diethylzinc to benzaldehyde was investigated.All soluble polymeric chiral BINOL ligands were characterized by IR、 1H-NMR、GPC and elemental analysis,which clearly demonstrated the formation of polymeric chiral BINOL ligands.These soluble polymeric chiral ligands were found to be effective in the addition of diethylzinc to benzaldehyde either in the presence or in the absence of Ti（Oi Pr）4 with higher catalytic activities and lower enantioselectivities.In the latter case,the dendritic chiral BINOL ligands showed much higher catalytic activity and a little higher enantioselectivity than BINOLs.
